Pallet with extruded composite support blocks and associated methods of making the same

ABSTRACT

A pallet includes a cargo layer and a base layer, and a plurality of support block assemblies separating the cargo and base layers. Each support block assembly includes first and second support blocks. The first support block has a first opening extending therethrough in a horizontal direction, and the second support block has a second opening extending therethrough in the horizontal direction. The second support block is inserted into the first opening of the first support block.

FIELD OF THE INVENTION

The present invention relates to the field of pallets, and moreparticularly, to a pallet with extruded composite support blocks, andrelated methods for making the same.

BACKGROUND OF THE INVENTION

Conventional pallets are typically made of wood and include a base layerand a cargo layer separated therefrom by support blocks. The base andcargo layers are also referred to as bottom and top decks.

Traditionally, the base and cargo layers are multiple layers, with eachlayer respectively having end deck boards assembled on connector boardsthat run the full length or width of the pallet. The end deck boards arenailed through the connector boards into the support blocks to build theprimary structure of the pallet. The end deck boards are also known aslead boards. Intermediate deck boards are placed between the end deckboards. Alternatively, the base layer may be a single layer where theend deck boards do not overlap the connector boards.

To move the pallet with cargo thereon, tines from a forklift or a palletjack are inserted into the gaps between the base and cargo layers on alead board side of the pallet. In certain instances, the tines of theforklift or pallet jack may make contact with the support blocks duringalignment. If the force is significant, the support blocks may bedamaged.

The support blocks are generally solid wood. Solid wood support blocksprovide good strength and durability. Depending on their size, solidwood support blocks can be heavy which adds to the final weight of thepallet. The cost of each solid wood support block is typically based onits volume and the type of wood used.

As an alternative to solid wood support blocks, composite materials maybe used. U.S. published patent no. 2011/0192326 to Ingham discloses apallet comprising a first deck, a second deck, and a plurality ofsupport blocks connecting the first and second decks together to form apallet. The support blocks include at least one recycled thermoplasticcomponent including at least about 20% by weight of a recycled nyloncarpet material.

Ingham discloses that the composite solid support blocks may havedifferent shapes and geometries. To form the composite support blocks,compression molding, injection molding, or extrusion techniques may beused. Solid composite support blocks are not readily adaptable toextrusion due to the thickness of the composite material. If thecomposite material includes plastic, the plastic may get deformities ifit does not cool well.

As an alternative to solid composite support blocks, Ingham furtherdiscloses a hollow composite support block with a substantiallyrectangular shaped top with rounded corner areas and a hollow centerarea. The thinner walls of the hollow support block cool faster whenextruded. While the hollow composite support block has a reduced weightand volume as compared to a solid support block, it may not be strongenough to withstand heavy pallet loads because of the thinner walls.Consequently, there is a need for composite hollow support blocks thatare lightweight while supporting heavy pallet loads.

SUMMARY OF THE INVENTION

A pallet includes a cargo layer, a base layer, and a plurality ofsupport block assemblies separating the cargo and and base layers. Eachsupport block assembly may comprise a first support block with a firstopening extending therethrough in a horizontal direction, and a secondsupport block with a second opening extending therethrough in thehorizontal direction. The second support block may be inserted into thefirst opening of the first support block. The support block assembly isa hollow structure which advantageously reduces weight and cost ascompared to a single solid support block, yet still provides strengthand durability to support heavy pallet loads.

The second opening in the second support block may be orthogonal withthe first opening in the first support block so as to enclose the secondopening. In this embodiment, exposed outer sidewalls of the secondsupport block may be aligned with exposed outer sidewalls of the firstsupport block. Interfaces between the exposed outer sidewalls of thefirst and second support blocks may be hermetically sealed. Ahermetically sealed support block assembly prevents fasteners from beingexposed within the second opening, as well as preventing dirt and waterfrom accumulating within the second opening.

The pallet may further comprise a plurality of fasteners coupling thecargo and base layers to the plurality of support block assemblies, withthe plurality of fasteners extending into the respective second openingsof the second support blocks.

The first support block may be rectangular shaped and the first openingextending therethrough may also be rectangular shaped. The secondsupport block may be rectangular shaped and the second opening extendingtherethrough may also be rectangular shaped.

The first and second support blocks may comprise a composite material.The composite material may comprise wood and plastic. The compositematerial may comprise about 50% wood and about 50% plastic, for example.The wood may comprise at least one of wood dust and wood waste, and theplastic may comprise recycled plastic. The cargo and base layers mayeach comprise a plurality of wood boards.

Another aspect is directed to a method for making a pallet comprisingproviding a cargo layer and a base layer, and forming a plurality ofsupport block assemblies separating the cargo and and base layers.Forming each support block assembly may comprise forming a first supportblock with a first opening extending therethrough in a horizontaldirection, and forming a second support block with a second openingextending therethrough in the horizontal direction. The second supportblock may be inserted into the first opening of the first support blockto form the support block assembly. The method may further comprisecoupling the cargo and base layers to the plurality of support blocks.To form the first and second support blocks, extrusion techniques mayadvantageously be used.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a pallet with extruded composite supportblock assemblies in accordance with the present invention.

FIG. 2 is a perspective view of a first support block from the supportblock assembly illustrated in FIG. 1.

FIG. 3 is a perspective view of a second support block from the supportblock assembly illustrated in FIG. 1.

FIG. 4 is a perspective view of the second support block partiallyinserted into the first support block so as to form the support blockassembly illustrated in FIG. 1.

FIG. 5 is a perspective view of the support block assembly illustratedin FIG. 1.

FIG. 6 is a perspective view of an alternative embodiment of the supportblock assembly illustrated in FIG. 5.

FIGS. 7-9 are top and side views with dimensions for the first supportblock illustrated in FIG. 2.

FIGS. 10-12 are top and side views with dimensions for the secondsupport block illustrated in FIG. 3.

FIG. 13 is a partial cross-sectional view of a corner of the palletillustrated in FIG. 1 with fasteners coupling the cargo and base layersto a support block assembly.

FIG. 14 is flowchart for making the pallet with extruded compositesupport block assemblies as illustrated in FIG. 1.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention will now be described more fully hereinafter withreference to the accompanying drawings, in which preferred embodimentsof the invention are shown. This invention may, however, be embodied inmany different forms and should not be construed as limited to theembodiments set forth herein. Rather, these embodiments are provided sothat this disclosure will be thorough and complete, and will fullyconvey the scope of the invention to those skilled in the art. Likenumbers refer to like elements throughout, and prime notation is used toindicate similar elements in alternative embodiments.

Referring now to FIGS. 1-5, a pallet 20 with extruded composite supportblock assemblies 50 will be discussed. The pallet 20 includes a cargolayer 30, a base layer 40, and a plurality of support block assemblies50 separating the cargo and base layers, as illustrated in FIG. 1. Thesupport block assemblies 50 are at the corners of the pallet 20.Intermediate support blocks 55 are spaced between the between thesupport block assemblies 50.

Each support block assembly 50 includes a pair of hollow support blocks60, 70, with one support block positioned inside the other supportblock. Each intermediate support block 55 is a single solid supportblock. Alternatively, each intermediate support block 55 may also beconfigured to include a pair of hollow support blocks.

The illustrated cargo layer 30 includes end deck boards 32 assembled onconnector boards 34 that run the full length or width of the pallet 20.The end deck boards 32 are nailed through the connector boards 34 intothe support block assemblies 50. The end deck boards 32 are also knownas lead boards. Intermediate deck boards 36 are placed between the enddeck boards 32. The illustrated base layer 40 includes end deck boards42 that do not overlap the connector boards 44 so as to form a singlelayer.

The cargo and base layers 30, 40 are not limited to the illustratedembodiments, as readily appreciated by those skilled in the art. Forexample, the end deck boards 32 and the connector boards 34 in the cargolayer may not overlap so as to form a single layer. The boards in thecargo and base layers 30, 40 are typically wood.

More particularly, each support block assembly 50 includes a firstsupport block 60 with a first opening 62 extending therethrough, and asecond support block 70 with a second opening 72 extending therethrough,as illustrated in FIGS. 2 and 3. The first opening 62 in the firstsupport block 60 is aligned with the cargo and base layers 30, 40.Alignment means that the first support block 60 is orientated so thatthe first opening 62 extends in a horizontal direction. In other words,the first opening 62 extends in the same horizontal direction as thecargo and base layers 30, 40. Similarly, the second support block 70 isorientated so that the second opening 72 also extends in the horizontaldirection.

The second support block 70 is then inserted into the first opening 62of the first support block 60, as illustrated in FIG. 4. When fullyinserted, the two support blocks 60, 70 thus form the support blockassembly 50, as illustrated in FIG. 5. The support block assembly 50 isa hollow structure which reduces weight and cost as compared to a singlesolid support block, yet still provides strength and durability tosupport heavy pallet loads.

Still referring to FIG. 5, the second opening 72 in the second supportblock 70 is orthogonal with the first opening 62 in the first supportblock 60 so that the second opening is enclosed. In other words, thesecond support block 70 is rotated 90 degrees before being inserted intothe first opening 62 in the first support block 60. This configurationof the support block assembly 50 provides a hollow yet fully enclosedsupport block assembly. The exposed outer sidewalls 73 of the secondsupport block 70 are aligned with the exposed outer sidewalls 63 of thefirst support block 60.

In an alternative embodiment of the support block assembly 50′,orientation of the second support block 70′ is the same as the firstsupport block 60′ so that when the second support block is inserted intothe first support block, the second opening 72′ is exposed, asillustrated in FIG. 6.

Referring now to FIGS. 7-9, example dimensions of the first supportblock 60 will be discussed. In a top view, the first support block 60 is150 mm wide along edge 81 and 150 mm deep along edge 82. In a side viewlooking towards the first opening 62, a height of the first supportblock 60 is 100 mm along edge 83. A thickness of walls 84, 85 above andbelow the first opening 62 is 12.5 mm respectively so that a height ofthe first opening is 75 mm along edge 86. A thickness of walls 87, 88 tothe left and right of the first opening 62 is 15 mm respectively so thata width of the first opening is 120 mm along edge 89.

Referring now to FIGS. 10-12, example dimensions of the second supportblock 70 will be discussed. In a top view, the second support block 70is 150 mm wide along edge 91 and 120 mm deep along edge 92. In a sideview looking towards the second opening 72, a height of the secondsupport block 70 is 75 mm along edge 93. A thickness of walls 94, 95above and below the second opening 72 is 12.5 mm respectively so that aheight of the second opening is 50 mm along edge 96. A thickness ofwalls 97, 98 to the left and right of the second opening 72 is 15 mmrespectively so that a width of the second opening is 120 mm along edge99.

The first and second support blocks 60, 70 are formed using a compositematerial. The composite material is a mixture of wood and plastic. Moreparticularly, the wood includes wood dust and/or wood waste and theplastic includes, but is not limited to, plastic materials suitable foruse in a high strength composite material for a pallet, such asthermoplastic polymers resistant to many chemical solvents, bases andacids.

Thermoplastic polymers include polypropylene, polyethylene,polyurethane, polyvinylchloride, and poly(ethylene terephthalate), forexample. The plastic may be selected depending on the specific palletdesign, load capacity, and other requirements. The plastic may berecycled plastic, virgin plastic, or mixtures thereof.

The composite mixture for the support blocks 60, 70 may vary between40-60% wood and 60-40% recycled plastic. In one embodiment, thecomposite material includes 50% wood and 50% recycled plastic.

To form the composite support blocks 60, 70, compression molding,injection molding, or extrusion techniques may be used. Since thecomposite support blocks 60, 70 are hollow, extrusion is a preferredmanufacturing technique since the “thin” walls of each support blockcool within reasonable cycle times, as readily appreciated by thoseskilled in the art.

In addition, since the composite material includes plastic, heat may beused to seal off the outer exposed interfaces between the first andsecond support blocks 60, 70 so as to hermetically seal the secondopening 72. This is done for the configuration where the second opening72 in the second support block 70 is inserted orthogonal into the firstopening 62 of the first support block 60. A hermetically sealed secondopening 72 prevents the fasteners 100 from being exposed, as well aspreventing dirt and water from accumulating within the second opening72.

Referring now to FIG. 13, fasteners 100 are used to couple the boards inthe cargo layer 30 to a top side of the support block assembly 50, andto couple the boards in the base layer 40 to a bottom side of thesupport block assembly 50. In the illustrated embodiment, the fasteners100 are nails. Other types of fasteners may be used, such as screws, forexample.

The fasteners 100 also hold the first and second support blocks 60, 70in place. The fasteners 100 extend through both the first and secondsupport blocks 60, 70. As a result, tips 102 of the fasteners areexposed within the second cavity 72. Another advantage of the first andsecond support blocks 60, 70 is that there is resiliency between thesupport block assembly 50 and the boards in the cargo and base layers30, 40. If the tines from a forklift, for example, hit the end deckboard 32 in the cargo layer 40, the impact force is transferred thoughthe fasteners 100 to the support block assembly 50. Movement or shiftingbetween the first and second support blocks 60, 70 help to absorb someof the impact.

Another aspect is directed to a method for making a pallet 20 asdescribed above. Referring now to the flowchart 110 illustrated in FIG.14, from the start (Block 112), the method comprises providing a cargolayer 30 and a base layer 40 at Block 114. The method further comprisesforming a first support block 60 with a first opening 62 extendingtherethrough in a horizontal direction at Block 116, and forming asecond support block 70 with a second opening 72 extending therethroughin the horizontal direction at Block 118. The second support block 70 isinserted into the first opening 62 of the first support block 60 atBlock 120 so as to form a support block assembly 50. The cargo and baselayers 30, 40 are then coupled to a plurality of support blockassemblies 50 at Block 122. The method ends at Block 124.

Many modifications and other embodiments of the invention will come tothe mind of one skilled in the art having the benefit of the teachingspresented in the foregoing descriptions and the associated drawings.Therefore, it is understood that the invention is not to be limited tothe specific embodiments disclosed, and that modifications andembodiments are intended to be included within the scope of the appendedclaims.

1. A pallet comprising: a cargo layer; a base layer; and a plurality of support block assemblies separating said cargo and base layers, each support block assembly comprising a first support block with a first opening extending therethrough in a horizontal direction, and a second support block with a second opening extending therethrough in the horizontal direction, and said second support block inserted into the first opening of said first support block, with interior dimensions of the first opening in said first support block corresponding to exterior dimensions of a single second support block.
 2. The pallet according to claim 1 wherein the second opening in said second support block is orthogonal with the first opening in said first support block so as to enclose the second opening.
 3. The pallet according to claim 2 wherein exposed outer sidewalls of said second support block are aligned with exposed outer sidewalls of said first support block.
 4. The pallet according to claim 3 wherein interfaces between the exposed outer sidewalls of said first and second support blocks are sealed.
 5. The pallet according to claim 1 further comprising a plurality of fasteners coupling said cargo and base layers to said plurality of support block assemblies, with said plurality of fasteners extending into respective second openings of said second support blocks.
 6. The pallet according to claim 1 wherein said first support block is rectangular shaped and the first opening extending therethrough is also rectangular shaped, and wherein said second support block is rectangular shaped and the second opening extending therethrough is also rectangular shaped.
 7. The pallet according to claim 1 wherein said first and second support blocks comprise a composite material.
 8. The pallet according to claim 7 wherein the composite material comprises wood and plastic.
 9. The pallet according to claim 8 wherein the composite material comprises about 50% wood and about 50% plastic.
 10. The pallet according to claim 8 wherein the wood comprises at least one of wood dust and wood waste, and wherein the plastic comprises recycled plastic.
 11. The pallet according to claim 1 wherein said cargo and base layers each comprises a plurality of wood boards.
 12. A pallet comprising: a cargo layer; a base layer; and a plurality of composite support block assemblies separating said cargo and base layers, each composite support block assembly comprising a first composite support block with a first opening extending therethrough in a horizontal direction, a second composite support block with a second opening extending therethrough in the horizontal direction, said first and second composite support blocks comprising a composite material comprising wood and plastic, and said second composite support block inserted into the first opening of said first composite support block, with the second opening being orthogonal to the first opening in said first composite support block so as to enclose the second opening.
 13. The pallet according to claim 12 wherein exposed outer sidewalls of said second composite support block are aligned with exposed outer sidewalls of said first composite support block.
 14. The pallet according to claim 13 wherein interfaces between the exposed outer sidewalls of said first and second composite support blocks are sealed.
 15. The pallet according to claim 12 further comprising a plurality of fasteners coupling said cargo and base layers to said plurality of composite support block assemblies, with said plurality of fastener extending into respective second openings of said second composite support blocks.
 16. The pallet according to claim 12 wherein the composite material comprises about 50% wood and about 50% plastic.
 17. The pallet according to claim 12 wherein the wood comprises at least one of wood dust and wood waste, and wherein the plastic comprises recycled plastic.
 18. A method for making a pallet comprising: providing a cargo layer and a base layer; forming a plurality of support block assemblies separating the cargo and base layers, forming each support block assembly comprising forming a first support block with a first opening extending therethrough in a horizontal direction, and forming a second support block with a second opening extending therethrough in the horizontal direction, and inserting the second support block into the first opening of the first support block, with interior dimensions of the first opening in the first support block corresponding to exterior dimensions of a single second support block; and coupling the cargo and base layers to the plurality of support blocks.
 19. The method according to claim 18 wherein the second opening in the second support block is orthogonal with the first opening in the first support block so as to enclose the second opening.
 20. The method according to claim 19 wherein exposed outer sidewalls of the second support block are aligned with exposed outer sidewalls of the first support block.
 21. The method according to claim 20 further comprising sealing interfaces between the exposed outer sidewalls of the first and second support blocks.
 22. The method according to claim 18 wherein the coupling comprises using a plurality of fasteners, with the plurality of fasteners extending into respective second openings of the second support blocks.
 23. The method according to claim 18 wherein the first and second support blocks are extruded.
 24. The method according to claim 18 wherein the first support block is rectangular shaped and the first opening extending therethrough is also rectangular shaped, and wherein the second support block is rectangular shaped and the second opening extending therethrough is also rectangular shaped.
 25. The method according to claim 18 wherein the first and second support blocks comprise a composite material, with the composite material comprising wood and plastic. 